Crack-fabrication techniques and their effects on the fracture toughness and CTOD for fresh-water columnar ice

Abstract The effects of notch acuity (crack-tip sharpness) on the fracture toughness of S2 ice were investigated using six groups of single-edge-notched-bend (SENB) specimens with different crack (or notch) root radii fabricated by six different methods. The mean value and standard deviations of the...

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Bibliographic Details
Published in:Journal of Glaciology
Main Authors: Wei, Y., DeFranco, S.J., Dempsey, J. P.
Format: Article in Journal/Newspaper
Language:English
Published: Cambridge University Press (CUP) 1991
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Online Access:http://dx.doi.org/10.1017/s0022143000007280
https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000007280
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Summary:Abstract The effects of notch acuity (crack-tip sharpness) on the fracture toughness of S2 ice were investigated using six groups of single-edge-notched-bend (SENB) specimens with different crack (or notch) root radii fabricated by six different methods. The mean value and standard deviations of the apparent fracture-toughness values K Q of the specimens with blunt notches were significantly higher than those of the specimens with sharp cracks. The results presented in a plot of fracture toughness versus , where p is the crack-tip radius, provide an estimate of the required notch acuity for fracture-toughness testing. The microstructural features in the immediate vicinity of the crack tip and the crack-tip geometry govern the magnitude of the apparent fracture toughness of the ice. The crack-tip-opening-displacement (CTOD) measured in this study indicates the existence of microplastic deformation in the vicinity of the crack tip at the initiation of unstable fracture.